In this adult stepsister role-play, my mother introduced her as the sister I would be living with from that day on, and something immediately stirred inside me. The little tease quickly realized I was a virgin and began tormenting me at every opportunity. She made sure I could see her having sex with her biological father, then forced herself on both of my friends. She may not have been related to me by blood, but she was still my sister. Even so, there was no way I could keep resisting...